grep: This is GNU grep, the "fastest grep in the west"1

GNU grep is based on a fast lazy-state deterministic matcher
(about twice as fast as stock Unix egrep) hybridized with a
Boyer-Moore-Gosper search for a fixed string that eliminates
impossible text from being considered by the full regexp
matcher without necessarily having to look at every character. The
result is typically many times faster than Unix grep or
egrep.